Field
Apparatuses and methods consistent with exemplary embodiments relate to a display apparatus and an echo cancellation method thereof, and more particularly to a display apparatus which can suppress a residual echo and an echo cancellation method thereof.
Description of the Related Art
A display apparatus such as a television (TV), a portable apparatus such as a mobile terminal, or a similar electronic apparatus can support functions such as voice recognition for recognizing a user's voice to control a device, a video call or video conference using a user's voice, etc. and a use range of these functions based on a voice have been gradually extended. The apparatus supporting such functions uses a microphone to receive a voice signal, and the received voice signal may include an echo.
The echo is results from a sound wave propagating from a sound source and reflecting off an object. Such an echo is easy to hear in daily life, and there is a sound reverberating from a mountain as an example of a simple echo based on a single reflection.
In contrast with the echo, there is a direct sound. The direct sound refers to a sound that is heard directly without being reflected off an object. Hence, the echo is a reflection of sound arriving a predetermined time after the direct sound.
In general, a sound made inside a structure with reflective surfaces, such as a room where a TV is installed, is reflected many times and becomes complex since directions of reflected sounds are all different. This is an example of multiple echoes, and is one of causes of a residual echo. For instance, the residual echo may be caused when a sound output from a speaker is reflected many times and then returned to a microphone.
If an echo and a residual echo are not properly canceled from an input voice signal, it may inconvenience a user who is using a corresponding function and may cause an error in operation. For a normal operation, not only the echo but also the residual echo has to be canceled from the voice signal.
However, the existing cancellation for the echo or the residual echo becomes a burden to an apparatus in light of a processing time or load since the existing cancellation generally needs complicated calculations, and has a disadvantage that the residual echo is not effectively canceled.